Cataract surgery is one of the most frequently performed operations in the world. For decades, the retrobulbar block was the dominant anesthetic technique, delivering local anesthetic into the intraconal orbital compartment to achieve both analgesia and akinesia of the eye¹. Today, however, the retrobulbar block has been substantially displaced by more efficient alternatives, and recent survey data confirm that its use has diminished to a small fraction of cataract procedures worldwide.
Because the needle must be directed into the intraconal space posterior to the globe and in close proximity to the optic nerve for a retrobulbar block, the potential for injury is inherent to the technique. Possible complications include optic nerve injury, retrobulbar hemorrhage, and globe perforation². Central nervous system involvement, including brainstem anesthesia, has been reported in 0.09% to 1.50% of patients, and orbital hemorrhage occurs in roughly 1.7%². These rates, while low in absolute terms, reflect a risk profile more severe than that of alternative techniques. The original Atkinson method compounded these dangers by instructing patients to direct their eyes upward and inward during needle insertion, a maneuver that places the optic nerve in a stretched, taut configuration directly in the needle’s path¹.
Efforts to make the retrobulbar block safer led to meaningful technical refinements. Hamilton described a modified inferotemporal approach in which the needle entry point was shifted to the lower temporal rim of the orbit, the needle was advanced parallel to the orbit floor with the globe in primary gaze, and penetration depth was limited to 31 mm—changes designed to reduce the risk of optic nerve contact and extraocular muscle injury¹. In a series of 8,500 cataract procedures using this modified technique combined with a complementary medial periconal block, no cases of postoperative diplopia attributable to needle trauma or anesthetic myotoxicity were recorded¹. Although such refinements demonstrated that the retrobulbar block could be performed with greater safety, they did not halt the broader shift in practice toward less invasive options.
Contemporary practice has increasingly favored topical anesthesia, potentially with intracameral lidocaine injection and/or sedation, as the primary technique for routine cataract surgery. A 2022 survey found that nearly 48% of ophthalmologists in the survey group preferred topical anesthesia combined with intracameral injection, and a further 41% preferred topical anesthesia alone³. By contrast, 1.4% preferred the retrobulbar block³. The predominant reasons cited for these preferences were patient comfort and ease of technique, and the trend away from sharp-needle blocks was explicitly noted by the study authors as consistent with practice patterns observed across multiple countries including Canada, Singapore, and South Korea³.
The sub-Tenon block presents a viable alternative for cataract surgery that has facilitated the declining use of the retrobulbar block. Rather than using a sharp needle directed posteriorly through the orbit, sub-Tenon anesthesia involves a small scleral incision through which a blunt cannula delivers local anesthetic beneath Tenon’s fascia². This approach provides effective analgesia and akinesia with a more favorable safety profile than the retrobulbar technique. A randomized, double-blind prospective study comparing all three major techniques—retrobulbar block, sub-Tenon block, and topical anesthesia—found that while the retrobulbar block produced superior intraoperative analgesia and reduced sedation requirements, it also generated significantly higher pain scores at the time of block administration and caused pronounced hemodynamic responses, with tachycardia observed in 15 of 27 retrobulbar patients and hypertension in 12 of 27⁴. Patients receiving the sub-Tenon block reported the highest overall satisfaction scores on the Iowa Satisfaction with Anesthesia Scale, a finding the authors attributed to the balance of effective perioperative pain control and the absence of severe injection-related discomfort⁴.
The literature describes a coherent evolution in ophthalmic anesthetic practice. The retrobulbar block, though capable of producing excellent akinesia, carries non-trivial risks, generates substantial patient discomfort at the moment of injection, and is technically difficult²,⁴. Growing preference for topical anesthesia, driven by advances in phacoemulsification that have shortened operative times and reduced the need for akinesia, and sub-Tenon techniques with their improved safety profiles have together rendered the retrobulbar block unpopular for routine cataract surgery²,³.
References
1. Hamilton, R. C. Retrobulbar block revisited and revised. J. Cataract Refract. Surg. 22, 1147–1150 (1996). https://doi.org/10.1016/S0886-3350(96)80062-9
2. Pucchio, A. et al. Anesthesia for ophthalmic surgery: an educational review. Int. Ophthalmol. (2022). https://doi.org/10.1007/s10792-022-02564-3
3. Hamid, M., Shiwani, H. A. & Hamid, F. A survey of anaesthetic preferences in cataract surgery. Int. J. Ophthalmol. 15, 342–345 (2022). https://doi.org/10.18240/ijo.2022.02.22
4. Ryu, J.-H. et al. A comparison of retrobulbar block, sub-Tenon block, and topical anesthesia during cataract surgery. Eur. J. Ophthalmol. 19, 240–246 (2009). https://doi.org/10.1177/112067210901900211